在Unity中创建2D圆形网格 [英] Creating a 2D Circular Mesh in Unity
问题描述
我目前有一个"CreateMesh"脚本，可以将其作为带有Mesh Renderer和Mesh Filter的对象的一个组件放置，并使用多边形对撞机在网格尺寸上创建2D网格，并给出""MeshType"变量设置为"tri"或"box"(分别用于三角形和矩形网格.)我还想添加创建圆形网格的功能，但是根据一些研究，我意识到这并不是那么简单就像我第一次想到的那样但是，我还没有找到任何有帮助的方法.
I currently have a "CreateMesh" script that can be put as a component of an object with a Mesh Renderer, and a Mesh Filter, and a 2D mesh is created with a polygon collider in the dimensions of the mesh given a "MeshType" variable is set to either "tri" or "box" (for a triangle and rectangle mesh respectively.) I want to also add the ability to create a circular mesh however from some research I've realised this isn't as simple as I first thought. However I'm yet to find anything that's helping.
这是框和三角形网格的代码:
This is the code I have for the box and triangle meshes:
public float width = 5f;
public float height = 5f;
public string meshType;
public PolygonCollider2D polyCollider;
void Start()
{
polyCollider = GetComponent<PolygonCollider2D>();
}
// Update is called once per frame
void Update () {
if (meshType == "tri")
{
TriangleMesh(width, height);
}
if (meshType == "box")
{
BoxMesh(width, height);
}
}
void TriangleMesh(float width, float height)
{
MeshFilter mf = GetComponent<MeshFilter>();
Mesh mesh = new Mesh();
mf.mesh = mesh;
//Verticies
Vector3[] verticies = new Vector3[3]
{
new Vector3(0,0,0), new Vector3(width, 0, 0), new Vector3(0, height, 0)
};
//Triangles
int[] tri = new int[3];
tri[0] = 0;
tri[1] = 2;
tri[2] = 1;
//normals
Vector3[] normals = new Vector3[3];
normals[0] = -Vector3.forward;
normals[1] = -Vector3.forward;
normals[2] = -Vector3.forward;
//UVs
Vector2[] uv = new Vector2[3];
uv[0] = new Vector2(0, 0);
uv[0] = new Vector2(1, 0);
uv[0] = new Vector2(0, 1);
//initialise
mesh.vertices = verticies;
mesh.triangles = tri;
mesh.normals = normals;
mesh.uv = uv;
//setting up collider
polyCollider.pathCount = 1;
Vector2[] path = new Vector2[3]
{
new Vector2(0,0), new Vector2(0, height), new Vector2(width, 0)
};
polyCollider.SetPath(0, path);
}
void BoxMesh(float width, float height)
{
MeshFilter mf = GetComponent<MeshFilter>();
Mesh mesh = new Mesh();
mf.mesh = mesh;
//Verticies
Vector3[] verticies = new Vector3[4]
{
new Vector3(0,0,0), new Vector3(0, height, 0), new Vector3(width, height, 0), new Vector3(width, 0, 0)
};
//Triangles
int[] tri = new int[6];
tri[0] = 0;
tri[1] = 1;
tri[2] = 3;
tri[3] = 1;
tri[4] = 2;
tri[5] = 3;
//normals
Vector3[] normals = new Vector3[4];
normals[0] = -Vector3.forward;
normals[1] = -Vector3.forward;
normals[2] = -Vector3.forward;
normals[3] = -Vector3.forward;
//UVs
Vector2[] uv = new Vector2[4];
uv[0] = new Vector2(0, 0);
uv[1] = new Vector2(0, 1);
uv[2] = new Vector2(1, 1);
uv[3] = new Vector2(1, 0);
//initialise
mesh.vertices = verticies;
mesh.triangles = tri;
mesh.normals = normals;
mesh.uv = uv;
//setting up collider
polyCollider.pathCount = 1;
Vector2[] path = new Vector2[4]
{
new Vector2(0,0), new Vector2(0, height), new Vector2(width, height), new Vector2(width, 0)
};
polyCollider.SetPath(0, path);
}
所以从本质上讲，我想要一个可以在update方法中调用的函数，该函数将简单地创建一个圆形网格.例如:
So essentially I want a function that I could call in the update method that would simply create a circular mesh. E.g:
void Update () {
if (meshType == "tri")
{
TriangleMesh(width, height);
}
if (meshType == "box")
{
BoxMesh(width, height);
}
if (meshType == "circle")
{
CircleMesh(radius);
}
}
推荐答案
我设法找到的解决方案包括创建一个n边的正多边形，其n值较大.我有一个称为PolyMesh的函数，该函数创建一个具有n个边和给定半径的规则多边形网格.
The solution I've managed to find involves creating a regular polygon of n sides with a large value of n. I have a function called PolyMesh which creates a regular polygon mesh with n sides and a given radius.
生成顶点
对于具有n边的规则多边形的每个顶点，相对于多边形中心的坐标由x = r*i*sin(θ)和y = r*i*cos(θ)给出，因此，x = r*i*sin(2π/2)和y = r*i*cos(2π/2)给出.我从0迭代到n-1.因此，我们可以得到一个分配了顶点的列表，然后将其转换为数组:
For each vertex of a regular polygon with n sides the coordinates relative to the centre of the polygon are given by x = r*i*sin(θ) and y = r*i*cos(θ) so therefore x = r*i*sin(2π/2) and y = r*i*cos(2π/2). Where i iterates from 0 to n-1. We can therefore have a list which has vertices assigned to it and then is converted to an array afterwards:
//verticies
List<Vector3> verticiesList = new List<Vector3> { };
float x;
float y;
for (int i = 0; i < n; i ++)
{
x = radius * Mathf.Sin((2 * Mathf.PI * i) / n);
y = radius * Mathf.Cos((2 * Mathf.PI * i) / n);
verticiesList.Add(new Vector3(x, y, 0f));
}
Vector3[] verticies = verticiesList.ToArray();
生成三角形
给定的n个边的规则多边形可以从同一点分为n-2个三角形.这样我们可以生成每个三角形，如下所示:
A given regular polygon of n sides can be split into n-2 triangles from the same point. So we can generate each triangle as follows:
//triangles
List<int> trianglesList = new List<int> { };
for(int i = 0; i < (n-2); i++)
{
trianglesList.Add(0);
trianglesList.Add(i+1);
trianglesList.Add(i+2);
}
int[] triangles = trianglesList.ToArray();
生成法线
因为这是一个2d对象，所以我们可以像-Vector3.forward这样将每个法线都设置为:
Since this is a 2d object we can have every normal as -Vector3.forward like so:
//normals
List<Vector3> normalsList = new List<Vector3> { };
for (int i = 0; i < verticies.Length; i++)
{
normalsList.Add(-Vector3.forward);
}
Vector3[] normals = normalsList.ToArray();
生成对撞机
我们可以只使用半径相同的圆碰撞器，但是为了使此函数适用于n值较小的多边形，我们必须使用PolygonCollider2D.由于顶点已在顶点数组中按顺序排列，因此我们可以简单地将它们用作PolygonCollider2D的路径.
We could just use a circle collider with the same radius but in order to make this function work for a polygon of a smaller value of n we must use a PolygonCollider2D. Since the vertices are already in order in the vertices array we can simply use them as the paths for our PolygonCollider2D.
//polyCollider
polyCollider.pathCount = 1;
List<Vector2> pathList = new List<Vector2> { };
for (int i = 0; i < n; i++)
{
pathList.Add(new Vector2(verticies[i].x, verticies[i].y));
}
Vector2[] path = pathList.ToArray();
polyCollider.SetPath(0, path);
完整的代码应如下所示:
The complete code should look like this:
public PolygonCollider2D polyCollider;
void Start()
{
polyCollider = GetComponent<PolygonCollider2D>();
}
void PolyMesh(float radius, int n)
{
MeshFilter mf = GetComponent<MeshFilter>();
Mesh mesh = new Mesh();
mf.mesh = mesh;
//verticies
List<Vector3> verticiesList = new List<Vector3> { };
float x;
float y;
for (int i = 0; i < n; i ++)
{
x = radius * Mathf.Sin((2 * Mathf.PI * i) / n);
y = radius * Mathf.Cos((2 * Mathf.PI * i) / n);
verticiesList.Add(new Vector3(x, y, 0f));
}
Vector3[] verticies = verticiesList.ToArray();
//triangles
List<int> trianglesList = new List<int> { };
for(int i = 0; i < (n-2); i++)
{
trianglesList.Add(0);
trianglesList.Add(i+1);
trianglesList.Add(i+2);
}
int[] triangles = trianglesList.ToArray();
//normals
List<Vector3> normalsList = new List<Vector3> { };
for (int i = 0; i < verticies.Length; i++)
{
normalsList.Add(-Vector3.forward);
}
Vector3[] normals = normalsList.ToArray();
//initialise
mesh.vertices = verticies;
mesh.triangles = triangles;
mesh.normals = normals;
//polyCollider
polyCollider.pathCount = 1;
List<Vector2> pathList = new List<Vector2> { };
for (int i = 0; i < n; i++)
{
pathList.Add(new Vector2(verticies[i].x, verticies[i].y));
}
Vector2[] path = pathList.ToArray();
polyCollider.SetPath(0, path);
}
这篇关于在Unity中创建2D圆形网格的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
